Improvement in machines for dressing millstones



2 Sheets-Sheet 1.

J. PEP-LEE Dressing Millstones. N0.109,046. I Patented N0v. 8, 1870.

2' Slieets Shet 2:

J. PEPLER.

Dressing Millstones.

Patented N0v.8,1870,

N. PETERS. PHOTO-LITHOGRAPHER, wASHiNGTON. D C.

cle, with openings A A, in which to mount and op- JAMES PEPLER, or

BATH, ENGLAND.

IMPROVEMENT IN MACIHINES FOR DRESSING MILLSTONES.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it'mcy concern Be it known that I, Janus PnPLEn, of Bath,Sum-l ersct county, England, tem porarilyresidin g at Toronto, Dominionof Canada, have invented certain newand useful Improvements in theConstruction of Machines for Dressing Millstones, of which the followingis a full, clear, and exact description, reference being bad to theaccompanying drawing, making part of this specification, in which-Figure 1 is a plan view of my machine placed upon a millstone;

Figure'2 is a side elevation; and

Figure 3 is a vertical cross-section through line .r y, 6 g. 1.-

Similar letters of reference denote corresponding parts in all thefigures.

Theiiuveution relates to that class of machines in which diamonds orother hard stones fixed in revolving disks are employed for cutting thecracks inthc, face of the stone. This class of machines may be dividedinto two sub-divisions, one of which includes those machines in whichthere is a device interposedbetween that part of the machine which restsupon the stone, and that part upon which the cutting appa-' tus ismounted, the object of this device being to level up the machiuetocompensate for the inequalities in the height of the different portionsof the stone upon which the feet may happen to rest. The otherconstruction referred to is that inwhich the way or track over which thecutting mechanism travels," is made practicably a part of and rigid withthe bed of the machine which rests upon the stone, involving nonecessity for any adjustment between the parts. Neither of theseconstructions has'ever been madeto accomplish the eud'sought for, thatis, to preserve a true and uniform face upon the stone; and with a viewto obviate the diiiiculties hitherto met with in the employment ofdiamonds for this purpose. I have invented tlicse improvements.

The invention consists in first constructing the base or bed in acircular form, for the purpose of obtaining, first, a perfect bearin gand an absolutely truthful average of the face of the stone; and second,of providing a support for both ends of the arm upon which the cuttingapparatus is mounted.

The invention further consists in adjusting the machine upon the stoneby means of girt or rest, extending across'the circle and secured inposition by means of a screw at each end, insuch manner that thetangential lines upon which the'lands are laid out, will be readilyconformcd to by the machine, in' a manner hereinafter explained.

In the drawing- A isthe bed or base, made preferably in a true cireratcthe cutting apparatus. This base should be made quite thin or narrowupon its under face, which rests upon the stone, for reasons which willbe made apparent.

B are the ways or guides, adj ustabl y secured to jaws c a of the.openings by means of bolts b' b.

Cis a tubular carrying-arm, provided with a female dovetail, G, at eachend, sliding upon ways B.

Upon arms 0 is supported the cutting apparatus usually employed indressing millstones with rotating diamonds, and-consisting of the sleeveD, cutter-frame l), spindles d, disks (1, set-screws (P, feed-screw 1G,ratchet-wheel c, cranks 0 c and spring pawl c.

l is a standard, provided with atubular arm, f, supporting shaft f, armF, poisef, and also the guiding-pulleys, ovcr'which passes thedriving-belt G.

The cutters are moved back and forth lengthwise of the lands by means oflever H, arm H, and links h h.

I is a girt, provided with a perforation, '1', to fit over the spindlein thcbed-stone, and overacenter which may be established in the eye ofthe runner.

1 I are thumb-screws at each end of this girt, for the purpose of makingcertain adjustments, as will be presently explained.

In locating the openings A A, care should be taken that the position ofjaw a be such that the path described by the diamond, when the same isretracted'as far as is possible toward saidjaw, shall be a linetangential to the eye of the stone, while, at the same time, the spindleof the stone shall occupy the center of the ring, and the openingsshould be of such width that the cutters may have roomenough to dressthree lands or an entire quarter, without moving the base, three beingthe number of adjacent lands that usually lie parallel with each other.

In operating my machine Iplace it upon the stone and proceed to locateit. This is done by placiugthe aperture 'i-OVGI the spindle or thecenter in the eye of the stone, which has'alrcady been referred to;then, by means of thumb-screws 1' I, I so adjust the machine, that thecutters shall traverse the lands in line parallel to the edges of saidlands lying next to the front side or deepestpart of the furrow. It isevident that, from the fact that all straight lines which may be drawnupon the face of a millstone are either radial or else tangential to acircle having its ceutercoincident with the center of the stone, I can,by means of girt I, so adjust the machine that I can dress an entirestone by merely swinging the machine upon i as a center, the machineitself being, as a whole, more or less eccentric to the stone upon whichit stands.

Having thus determined the location of the base, I

next proceed to form a seat for it thus: I turnit slowly around,dressing down the high points until I obtaina satisfactory seat ortrack, one which I am satisfied is time can truthful and accurate thisdone, I have a plane to which I can dress the entire stone with aperfect certainty, avoiding all liability to leaving the stone windingor undulating, as is the result of dressing with any of the machinesheretofore used. The preparationof this track involves but little labor,as the machine may be so constructed that its center shall be nearlycoincident with the center of the stone, when, with but a narrow or thinrim, the actual surface which it stands upon will be quite small.

It the drawing, owing to an imperfection in laying off the stone, theopenings-A. A arc'not represented as being wide enough to admit ofdressing all of the lands in a quarter, but it is designed in practiceto build the machine in such manner as will enable one to do so when itis considered advisable. The manner of operating the cutting apparatusis so closely analogous to that pursued in working the other machines ofthis class, that it is not deemed necessary to give a more detaileddescription'of it.

v It willhe observed that one of the openings is adapted to dress stonesthat run with the sun, and the other one those that run against the sun.When the arm is supported at one end only, as has been the caseheretofore, the outer end of it will yield a little vertically, thusallowing the cutter to ride over the hard spots, and to out deeper intothe softer spots in the stone, this motion of the arm growing out of thevdifliculty, in practice, of making the dovetail or other form of-wayfit with suflicient accuracy and tightness, while permitting freedom ofmotion of the parts, but,

7 by supporting both ends of said arm or shaft, the defeet is remedied.Of'course, it is not essential that both or either end of arms 0 shouldbe supported by a way of the precise form shown in fact, one end may beterminated by a simple tongue or tenon, and slide in a correspondinggroove, the most essential point being that both ways or tracks shalloccupy planes parallel to that occupied by the circular base, therebyenabling me to dress the entire face of the stone to the plane which Ihave established for the base to rest upon.

The girt I may, if preferred, be attached to and made adjustable uponthe flanges of the openings A A. One end of one of the tubular arms 0 isdepressed at such an angle as may he required for the purpose ofdressing the furrows.

I do not wish to' be understood as limiting-myself to the employment ofrotating diamonds in this machine, as it maybe found advantageous touseadiamond having a direct reciprocating motion, or even the ordinarypick operated by proper mechanism; because any cutting apparatus may beadapted to my machine without interfering with the features or principleembodied in my invention, the prominent element in-my construction beinga base which shall always rest upon the same portion of the stone, and,of course, always occupying the same plane'whatever may be its positionrelative to the different quarters or lands to vbe dressed.

Having now described my invention,

What I claim as new, and desire to secure by Letters Patent, isv 1. Thecircular base A, provided with openings, in which to mount thecuttingapparatus, substantially as set forth.

' 2. The base A, in combination with the cutting apparatus monntednponshaft 0, supported-abboth ends, substantially as .set forth.

3. The adjustable girt I, in combination with the bed A, substantiallyas set forth.

Witnesses-z JAMES PEPLER.

A. W. SHAW, A. R. FAULKNER.

